nfsd4: ignore WANT bits in open downgrade
[linux-2.6.git] / fs / ext4 / xattr_security.c
1 /*
2  * linux/fs/ext4/xattr_security.c
3  * Handler for storing security labels as extended attributes.
4  */
5
6 #include <linux/module.h>
7 #include <linux/string.h>
8 #include <linux/fs.h>
9 #include <linux/security.h>
10 #include <linux/slab.h>
11 #include "ext4_jbd2.h"
12 #include "ext4.h"
13 #include "xattr.h"
14
15 static size_t
16 ext4_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
17                 const char *name, size_t name_len, int type)
18 {
19         const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
20         const size_t total_len = prefix_len + name_len + 1;
21
22
23         if (list && total_len <= list_size) {
24                 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
25                 memcpy(list+prefix_len, name, name_len);
26                 list[prefix_len + name_len] = '\0';
27         }
28         return total_len;
29 }
30
31 static int
32 ext4_xattr_security_get(struct dentry *dentry, const char *name,
33                        void *buffer, size_t size, int type)
34 {
35         if (strcmp(name, "") == 0)
36                 return -EINVAL;
37         return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
38                               name, buffer, size);
39 }
40
41 static int
42 ext4_xattr_security_set(struct dentry *dentry, const char *name,
43                 const void *value, size_t size, int flags, int type)
44 {
45         if (strcmp(name, "") == 0)
46                 return -EINVAL;
47         return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
48                               name, value, size, flags);
49 }
50
51 int
52 ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
53                    const struct qstr *qstr)
54 {
55         int err;
56         size_t len;
57         void *value;
58         char *name;
59
60         err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
61         if (err) {
62                 if (err == -EOPNOTSUPP)
63                         return 0;
64                 return err;
65         }
66         err = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_SECURITY,
67                                     name, value, len, 0);
68         kfree(name);
69         kfree(value);
70         return err;
71 }
72
73 const struct xattr_handler ext4_xattr_security_handler = {
74         .prefix = XATTR_SECURITY_PREFIX,
75         .list   = ext4_xattr_security_list,
76         .get    = ext4_xattr_security_get,
77         .set    = ext4_xattr_security_set,
78 };